Composite components may be manufactured using the resin transfer molding (RTM) method. In this type of manufacture of composite components a fibrous mat is arranged in a molding-tool cavity of a molding tool, and thereafter when the molding tool is completely closed, is impregnated with resin. The fibrous mat may be designed in various ways, for example it may comprise individual non-interwoven fibers, a woven fiber fabric or a fibrous web. The fibers may, for example, be carbon fibers. While the fibrous mat is being impregnated with resin, as a rule synthetic resin such as, for example, epoxy resin, the liquid resin fully takes up the space in the molding-tool cavity. Subsequently, the resin cures or solidifies within the molding-tool cavity, for example as a result of a chemical reaction triggered by heating the resin, and a composite component is produced that comprises the fibrous mat and the cured resin.
From DE 10 2005 053 691 A1 or WO 2007 054 268 A1 a molding tool for implementing the RTM method is known. During the curing process the volume of resin is reduced up to approximately 3%. With the use of semi-finished fiber products with additional material that during infiltration by the resin dissolves with the resin, for example in order to modify mechanical characteristics of the resin, the volume of the semi-finished fiber product after infiltration may be reduced by up to approximately 20% when compared to the state before infiltration. This may result in a situation in which, above all in the case of a composite component comprising particularly thick sections, as a result of volume shrinkage the composite component no longer has the geometry defined by the molding-tool cavity. Furthermore, because the pressure in the molding tool is reduced as a result of shrinkage, blistering may occur in the composite component, which blistering reduces the local strength of the composite component.
From EP 1 013 409 A2 a method is known in which instead of an inflexible counter-mold a flexible membrane is used. A fibrous mat is placed on an inflexible negative mold and is covered by means of the flexible membrane. Counter-pressure is applied to the membrane so that a molded part arises whose one side is shaped like the negative mold. No predefined geometry may be specified for the other side, which rests against the flexible membrane, of the composite component to be manufactured.
In view of the foregoing it is at least one object to be able to produce composite components of uniform strength and precisely predetermined geometric shapes. In addition, other objects, desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.